There was a car inspector at the top of Marshall Pass. There was a reference to the car inspector in the ICC report on the Aug. 6, 1935 runaway of the 492 near Mears Junction. The car inspector performed the air test and found the train to be within the leakage limits.
I am familiar with the wreck because my mother grew up in Salida. Her friend, Jesse Boots, lost her dad in that wreck. Ed Boots was the head brakeman who was on top of 492's tender when it ran away. He had no place to jump so he rode out the runaway and then train piled up on him.
BTW the train made three setouts after leaving Marshall.
The most likely cause was a closed angle by a hobo although the report lists the cause as unknown.